Play and optimal welfare: Does play indicate the presence of positive affective states?

Abstract

Play is commonly used to assess affective states in both humans and non-human animals. Play appears to be most common when animals are well-fed and not under any direct threats to fitness. Could play and playfulness therefore indicate pre-existing positive emotions, and thence optimal animal welfare? We examine this question by surveying the internal and external conditions that promote or suppress play in a variety of species, starting with humans. We find that negative affective states and poor welfare usually do suppress play (although there are notable exceptions where the opposite occurs). Furthermore, research in children suggests that beyond the frequency or total duration of play, poor welfare may additionally be reflected in qualitative aspects of this heterogeneous behaviour (e.g. display of solitary over social play; and the 'fragmentation' of play bouts) that are often overlooked in animals. There are surprisingly few studies of play in subjects with pre-existing optimal welfare or in unambiguously highly positive affective states, making it currently impossible to determine whether play can distinguish optimal or good welfare from merely neutral welfare. This therefore represents an important and exciting area for future research.

What is animal happiness?

“…One advantage of the affect balance measurements is that it enables us to assess absolute positive and negative states rather than simply relative positive and negative states. 77 A negative ratio-a higher frequency of negative over positive affectreflects an absolute negative state, with the number of the ratio indicating how negative this is. A positive ratio-a higher frequency of positive over negative affect-reflects an absolute positive state.…”

Assessing Affective State in Laboratory Rodents to Promote Animal Welfare—What Is the Progress in Applied Refinement Research?

“…A promising approach for the evaluation of positive affective states is the assessment of social behaviors like play. Social play behavior, especially play fighting or rough-and-tumble play, is particularly abundant during juvenile and adolescent development in humans and animals [31,32]. As social play covers a diverse assemblage of behaviors, there exists a list of characteristics describing play behavior rather than a strict definition.…”

“…Essentially, play behavior is usually carried out in a positive life context or is suppressed within unpleasant situations and, therefore, may indeed act as a welfare indicator [31]. For example, the structural enrichment of larger cages leads to enhanced play behavior in juvenile rats [33].…”

Assessing the welfare of kennelled dogs—A review of animal-based measures

“…Therefore, a thorough assessment of kennel dog welfare should also include measures of positive behaviours, such as the willingness/desire to engage in play. Level of play behaviour has been found a useful measure of welfare in a myriad of other species such as cattle, sheep, deer, cats, wolves, meerkats, seals, rats, chimpanzees and of course humans (for reviews, see: Ahloy-Dallaire et al, 2017, andHeld andŠpinka, 2011). Kiddie and Collins (2014) included "willingness to play" as an indicator of positive emotional states in their shelter dog quality of life assessment and measured this through recording both unprovoked play behaviours in the kennel (both solitary and with other dogs) as well as initiated play, where the assessor engaged the dog with a "Ragger".…”

“…Barnard et al (2014) included the term "playful" in their Emotional State Profile as an indicator of positive emotional state. It should however be noted that a decrease in negative affect does not necessarily equate with the presence of an absolute positive affective state (Ahloy-Dallaire et al, 2017). It may be that negative states prevent play and therefore, on its own, willingness to play cannot be used a definitive sign that an animal has good welfare.…”